Outdoor fence mural

We are attempting to put up plywood along the inside of the two horizontal supports on our fence to paint a mural. It will be about 2' high and run 82'. We plan on painting with our children and would like the piece to last a long time, preventing warping, peeling and fading as long as possible.

How do we treat, paint and seal regular plywood? Would an oil based primer, latex exterior paint and a clear waterproof/UV resistance sealant work? Any other suggestions?